Combines are large self-propelled vehicles used for harvesting and threshing agricultural crop in the field. A harvesting head is typically disposed across the front of the combine vehicle supported on a feederhouse. This harvesting head is configured to cut and convey the crop into the combine vehicle itself where it is threshed, separated, and cleaned.
Traditional harvesting heads included an elongate rigid frame to which harvesting implements are added such as row units, reciprocating knife assemblies, augers, reels, and endless belt conveyors. One such type of harvesting head is called a “draper platform”, “draper header”, or more generally a “draper”.
Draper platforms have an elongate frame on which are mounted left and right side endless belt conveyors mounted immediately behind a reciprocating knife. These endless conveyors convey cut crop material inward to a center portion of the draper platform, depositing them on a center conveyor that moves rearward. The center conveyor carries the material to and through an aperture at the rear of the draper platform frame, where it is deposited in an elevating conveyor called a feederhouse, which carries the cut crop material into the combine vehicle for threshing, separating and cleaning.
In one arrangement, the reciprocating knife is mounted on pivoting support arms that extend forward from a rear transverse frame member. See US 2009/0249760 A1, FIGS. 1-11, in which the conveyors are stationary and the reciprocating knife moves up and down on parallelogram arms. This arrangement permits the entire cutter bar to flex up and down, severing the crop plants close to the ground.
In another arrangement, the left and right side conveyors have also been mounted on pivoting support arms. These support arms are generally horizontal and are pivotally connected to an elongate laterally extending frame member at their rear ends, and are connected to and support a reciprocating knife at their front ends. The pivoting arms permit both the conveyor belts and the reciprocating knife to move up and down to follow the terrain.
Prior art knife drives have been rigidly supported on arms extending forward from the frame of the draper platforms. This rigid support prevents the arms on which they are mounted from being pivotally coupled to the frame to thereby flex and follow the ground.
The problem to be solved is that of providing a flexible support for the knife drive elements such that the arms supporting the knife drive can pivot up and down to follow the terrain. This problem is solved by the arrangement described in claim 1. Further advantages are provided by additional claims that are dependent upon claim 1.